The present invention relates to an apparatus for and a method of automatically placing and routing, which automatically generates pattern data for a mask that is used in the photolithography process when manufacturing a semiconductor integrated circuit device.
As part of the manufacturing process for manufacturing a semiconductor integrated circuit device, there is a photolithography process in which a photosensitive resist having been coated onto the surface of a semiconductor wafer is exposed, via a mask having a desired mask pattern drawn therein, and then the resist is developed to form a resist mask. FIG. 8 and FIG. 9 each are a longitudinal sectional view illustrating how a metal distribution of a semiconductor integrated circuit apparatus is formed in the photolithography process. As illustrated in FIG. 8, for example, when forming a metal distribution, a metal distribution layer 13 is laminated via a layer insulation film 12 on a semiconductor wafer in which transistor etc. has been formed. Then, a resist film 14 is laminated on the surface of this metal distribution layer 13. Then, the resist film 14 is exposed using a mask 15 on which a distribution pattern has been drawn.
The resulting structure is developed as explained in FIG. 9. The exposed portion of the resist film is dissolved to thereby cause the non-exposed portion to remain as is. By performing etching treatment by using this remaining portion 16 as a mask, a metal distribution having a desired pattern is formed in the metal distribution layer 13. When the mask pattern is fine, the pattern width W2 of the actually obtained remaining resist portion 16 becomes inconveniently small in width compared to the pattern width W1 as initially designed due to the light proximity effect. Accordingly, the line width of the metal distribution that is obtained after performance of the etching treatment also becomes inconveniently narrower than the initially designed value.
FIG. 10 is a typical view illustrating part of a layout pattern that has been prepared using an automatic placing and routing apparatus. In the figure, the reference numeral 21 denotes a standard cell, and the reference numeral 22 denotes a distribution between the standard cells 21. The above-described narrowing of the distribution width due to the light proximity effect occurs at an end 22a (FIG. 11), or a bend 22b (FIG. 12) of the distribution 22. Namely, the line width of the end 22a or the bend 22b of the distribution 22 inconveniently becomes narrower than the originally designed value (the left side views in FIG. 11 and FIG. 12).
To account this, conventionally, as illustrated in FIG. 13, with respect to the end 22a or bend 22b of the distribution 22, preparation is made of data (hereinafter called xe2x80x9cadditional distribution dataxe2x80x9d) for providing additional distribution portions 23a, 23b for correcting the portion of the distribution where possibly the distribution width inconveniently becomes narrower in an actual process. These additional distribution portions 23a, 23b are generated using a layout verifying apparatus, after having prepared cell-assignment-pattern data and distribution-pattern data by using the automatic placing and routing apparatus.
FIG. 14 is a functional block diagram illustrating a conventional system for preparing the additional distribution data in accordance with the additional-distribution-data preparing procedure. With reference to this figure, the construction of this system will now be explained along with the additional-distribution-data preparing procedure. First, arrangement data and wire distribution data are prepared by the automatic placing and routing apparatus 31 to obtain source layout data 32. This source layout data 32 does not include the above-described additional distribution data.
Subsequently, using the source layout data 32 and a layout-verifying rule file 34 for generating additional distribution data, verification of the layout is performed by a layout verifying apparatus 33 to thereby obtain additional distribution data production information 35. According to the additional distribution data production information 35 and the source layout data 32, corrected layout data 36 containing the additional distribution data therein is obtained. And, using the corrected layout data 36 and a rule file 37 for verifying the layout data as a whole, verification of the layout is performed again by the layout verifying apparatus 33, thereby obtaining final pattern data 38 for use on a mask. This pattern data 38 for use on a mask includes the additional distribution data.
However, in the above-described conventional additional distribution data preparation method, a significantly longer time is needed for obtaining the final pattern data for use on a mask that includes the additional distribution data therein, so that the efficiency is disadvantageously poor.
The present invention has been made in order to solve the above-described problem and an object of the invention is to provide an apparatus for and a method of automatically placing and routing which, in a state of designing the mask used to manufacture a semiconductor integrated circuit device, makes it possible to quickly obtain final pattern data containing additional distribution data therein.
According to this invention, the cell assigning section automatically performs assignment of the cells according to the circuit data, the distribution path determining section automatically determines the distribution path between the cells that have been assigned, the distribution information extracting section extracts the information regarding the distribution path that has been determined, the prescribed-information recognizing section recognizes the information of a prescribed portion of the distribution according to information that has been extracted, the additional-distribution-data generating section generates the additional distribution data for correcting the width of distribution of the prescribed portion of the distribution that has been recognized, and the additional-distribution-data lay-out section lays out the additional distribution data that has been generated with respect to the prescribed portion of the distribution.
In this invention, the prescribed portion of the distribution may be an end or a bend of the distribution. With such a configuration, the prescribed-information recognizing section recognizes the information of the end or the bend as the prescribed portion of the distribution, the additional-distribution-data generating section generates the additional distribution data for correcting the width of distribution of the end or the bend of the distribution that has been recognized, and the additional-distribution-data lay-out section lays out the additional distribution data that has been generated with respect to the end or the bend of the distribution.
Further, a construction may be made wherein the additional-distribution-data lay-out section imparts a layer number different from that of the prescribed portion of the distribution to additional distribution data corresponding to this prescribed portion. With this configuration, the layer number of the prescribed portion of the distribution and the layer number of the additional distribution data corresponding to this prescribed portion become different from each other.
Further, a construction may be made wherein the additional-distribution-data generating section generates additional distribution data in such a way that a different size of additional distribution is laid out when the prescribed portion of the distribution is an end and when this prescribed portion is a bend. With this configuration, there is generated additional distribution data in such a way that a different size of additional distribution is laid out between when the prescribed portion of the distribution is an end and when this prescribed portion is a bend.
According to this invention, the assignment of the cells is automatically performed according to circuit data in the cell assigning step, the distribution path between the cells that have been assigned is automatically determined in the distribution path determining step, information regarding the distribution path that has been determined is extracted in the distribution information extracting step, information of a prescribed portion of the distribution is recognized according to the information that has been extracted in the prescribed-information recognizing step, additional distribution data for correcting the width of distribution is generated with respect to the prescribed portion of the distribution that has been recognized in the additional-distribution-data generating step, and the additional distribution data that has been generated is laid out with respect to the prescribed portion of the distribution in the additional-distribution-data lay-out step.
In this invention, the prescribed portion of the distribution may be an end or a bend of the distribution. With this configuration, in the prescribed-information recognizing step the information of the end or the bend as the prescribed portion of the distribution is recognized, in the additional-distribution-data generating step the additional distribution data for correcting the width of distribution is generated with respect to the end or the bend of the distribution that has been recognized, and in the additional-distribution-data lay-out step the additional distribution data that has been generated is laid out with respect to the end or the bend of the distribution.
Further, a construction may be made wherein in the additional-distribution-data lay-out step a layer number different from that of the prescribed portion of the distribution is imparted to additional distribution data corresponding to the prescribed portion. With this configuration, the layer number of the prescribed portion of the distribution and the layer number of the additional distribution data corresponding to this prescribed portion become different from each other.
Further, a construction may be made wherein in the additional-distribution-data generating step additional distribution data is generated in such a way that a different size of additional distribution is laid out when the prescribed portion of the distribution is an end and when this prescribed portion is a bend. With this configuration, there is generated additional distribution data in such a way that a different size of additional distribution is laid out when the prescribed portion of the distribution is an end and when this prescribed portion is a bend.
Other objects and features of this invention will become understood from the following description with reference to the accompanying drawings.